1. Field of the Invention
The present invention generally relates to new substituted ureas, to methods for preparing those substituted ureas and to agricultural uses of those substituted ureas to improve plant growth. More specifically, the present invention is directed to the reaction product formed by reacting a carboxylic acid with urea to form a new N,N′-di-substituted urea, to methods for conducting that reaction and to agricultural uses of the reaction product.
2. Description of the Background
Urea, being approximately 46% by weight nitrogen, has long been preferred as a nitrogen source for fertilizing soils to stimulate plant growth. However, urea suffers from high ammonia losses when used in the presence of moisture. This disadvantage effectively restricted the use of urea for many years. It is believed that these losses are caused by the hydrolysis of urea in the presence of moisture and the enzyme urease. The addition of a water soluble salt to aqueous solutions of urea has been suggested as a means for reducing ammonia volatilization. See U.S. Pat. No. 4,500,335. While substituted ureas are also known, e.g., diphenylurea, they have found little agricultural use.
Urea undergoes condensation reactions with carboxylic acids to produce barbituates and their analogs. These products have found no agricultural uses. However, the argicutural industry has felt the need for ways to improve early seedling vigor and to increase plant biomass, both resulting in improved yield. There has been a long felt but unfulfilled need in the industry for improved methods for achieving these goals. The present invention solves those needs.